1. Field of the Invention
The invention relates to a photocatalytic apparatus including photocatalytic material and a method for activating the photocatalytic material.
2. Description of the Related Art
It is known that a photocatalyst (i.e. photocatalytic material) activating by light rays with relatively short wavelength decomposes or dissolves the organic or inorganic substances, which are undesirable to humans and environments, such as bacteria, molds (i.e. fungus), nicotine, tar, tartar, colored scale, pollutants to cause environmental pollution and etc. When the substances approach to or come in contact with the photocatalyst activated by the light rays, they are subjected to oxidation and/or reduction reactions in order to be decomposed or dissolved by a photocatalyst effect, so that they are rendered harmless.
Typical photocatalyst is a kind of photo-activated semiconductor (i.e. photocatalytic semiconductor) such as titanium dioxide (TiO2).
Multiple photocatalyst particles (i.e. photocatalytic particles) are used as a form of photocatalyst supported substrate, in which a layer (i.e. film) including the photocatalyst particles is fixed and supported on the substrate, a recycling of the photocatalyst particles can be easily done because the separation and collection of the photocatalyst particles are not needed.
For example, the publication of unexamined patent application of Japan No. 155726/1993 discloses that Titanium Dioxide layer of the photocatalyst is coated on a substrate such as metal, ceramic and glass, for the purpose of protecting a surface of the substrate from growth of bacteria.
U.S. Pat. No. 4,526,570 issued on Jul. 2, 1985 to Nakagawa et al. discloses a dental hygienic device for hygienic treatment of teeth in an oral cavity (i.e. toothbrush), which is composed of a n-type semiconductor having a photoelectric effect using photoelectric chemical reaction, in which the semiconductor is disposed on or in a main body consisting of an insertion portion and a handle.
It is an object of the present invention is to provide a novel photocatalytic apparatus including photocatalytic material.
It is another object of the present invention is to provide a method for activating the photocatalytic material.
A first aspect of the present invention is a photocatalytic apparatus, which includes a substrate, fiber-like members (i.e. fibers, filaments, needles, bristles, whiskers), each of the fiber-like members including photocatalytic material, in which the fiber-like members are disposed on the substrate.
A second aspect of the present invention is a photocatalytic apparatus, which includes a substrate member being made of substantially transparent material, a plurality of fiber-like members, each of the fiber-like members including photocatalytic material and disposed on the substrate member, and the photocatalytic material being composed of a plurality of photocatalytic particles (i.e. powders, small elements, small pieces).
Each of the fiber-like members is preferably composed of a core including the photocatalytic particles. Each fiber-like member may be composed of a core and a sheath including the photocatalytic particles, instead.
The substrate member is preferably composed of a transparent body including light diffusing particles. The transparent body may have a first surface, a second surface and at least one side.
Each of the fiber-like members may be composed of a fiber-like body, a first end and a second end. The first end may be fixed on the first surface and/or the second surface and/or the side, while the second end is free end.
In addition to the fiber-like members including photocatalytic material, another fiber-like members excluding photocatalytic material may be used, in which both fiber-like members are disposed on the substrate.
A third aspect of the present invention is a method for activating photocatalytic material, which includes the step of providing a photocatalytic apparatus composed of a substrate member; a plurality of fiber-like members disposed on the substrate member, each of the fiber-like members including the photocatalytic material, irradiating light capable of activating the photocatalytic material to the fiber-like members, oxidizing/reducing one or more substances being in contact with or approaching to the fiber-like members by means of photocatalizing oxidization/reduction reactions.
A fourth aspect of the present invention is a method for activating photocatalytic material, which includes the step of providing a photocatalytic apparatus composed of a substantially transparent substrate member; a plurality of fiber-like members disposed on the transparent substrate member, each of the fiber-like members including photocatalytic material, introducing light capable of activating the fiber-like members into an interior of the transparent substrate member, transmitting the light in said interior; irradiating said light output from said interior to said fiber-like members, and oxidizing/reducing one or more objects being in contact with the fiber-like members by means of photocatalizing oxidization/reduction reactions.
At least one light guiding member may be interposed between at least one light source and the transparent substrate member from the light source to the transparent substrate in order to guide the light.
The light guide member may be composed of a transparent rod capable of transmitting the light. Alternatively, the light guide member may be composed of an optical fiber or an optical cable capable of transmitting the light.
The transparent rod may have a transparent sheath with lower refractive index than that of the transparent rod. Alternatively, the transparent rod may have a light reflective sheath made of a light reflective metal.
Photocatalyst material used for the present invention is a kind of photo-activated or photocatalytic semiconductor, such as Titanium Dioxide (TiO2), Tungsten Dioxide (WO2), Zinc Oxide (ZnO), Tin Dioxide (SnO2) and Zinc Sulfide (ZnS).
In the U.S. Pat. No. 4,526,570 to Nakagawa et al., a only sintered or coalesced semiconductor is used and the semiconductor does not disposed on brush bristles (i.e. fiber-like members), while in the present invention photocatalytic material is disposed on the fiber-like members. Further, in the present invention photocatalytic material is preferably composed of a plurality of photocatalytic particles, which are disposed on or in the fiber-like members.
It should be noted that the first aspect and the third aspect of the present invention have such advantages that an effective area of capable of coming in contact with or approaching to the photocatalyst material can be easily larger than the effective area of the prior art, because the photocatalytic material, preferably in a form of the plurality of photocatalytic particles, is disposed on the plurality of fiber-like members, and this structure also means that an effective area capable of receiving the light to activate the photocatalyst material can be easily larger than the prior art. Therefore, photocatalizing oxidation/reduction reactions can be remarkably accelerated by means of the first aspect and the third aspect of the present invention.
Further, it should be noted that the second aspect and the fourth aspect of the present invention have such advantages, in addition to the above-mentioned advantages, that the photocatalytic material can be irradiated effectively by the light output from the interior of the transparent substrate member, in which the light once inputs to the interior and outputs effectively in order to irradiate the photocatalytic fiber-like member after transmitting inside of the interior.